R151F Conversion to H151F

Gday
you need one petrol 100 series gearbox and transfer and driveshafts...and crossmember....and an 80 series diesel bellhousing and (either of these combos) turbo diesel clutch and flywheel....or std 1hz flywheel and a fzj75 clutchplate.
The reason you need 100 series 5 speed, is the gear shift is in a different place on the 80 box. The bells are interchangeable, the clutch spline is different on the h151 to the h150 (petrol to 1hz box)
Andrew

Kirsten, I have an HZJ105 (live axle) 1999, did the R151F gearbox and clutch in. I went to the wreckers with a tape measure and, after some other experiences, got the following:

H150F gearbox from HDJ79, with original rubber mount
80 series gearshift lever (7X series is wrong bend)
80 series transfer case (with internal oil pump; 100 series has only drip feed)
80 series transfer shift lever and mount (this was the hard part)
80 series T/D flywheel (don't bother getting the 100 series flywheel redrilled)
(new) T/D clutch kit (Toyota)

I used the bellhousing that came with the gearbox, but the 80 and 100 series appear identical.

The gearbox and tranny case meet up perfectly, and with the original rubber mount they fit straight into the HZJ105 crossmember, no mods required; you'll notice the offsets of the H and R series mounts are different which is why this works. The transfer case output drive flanges are in exactly the same locations (measured to within 2 mm) so you don't need mods to either driveshaft.

The 80 series transfer shift lever mount puts the transfer shift lever in exactly the right spot, all you need to do is retain the original top part of the lever (with the bend in it) from the 100 series - the 80 series one is too short and at the wrong angle.

The 80 series gearbox shift lever is ok, although as the 100 series has a larger base diameter I drilled out the internals of the top (rubber mounted) bit and pressed it on to the cut-down 80 series lever.

The 105 wiring loom will just reach all the switches, but you do have to do a bit of unwinding and retaping as it is otherwise too short.

I tore down both the gearbox and transfer case for inspection. Replaced input gear and third plus all bearings in the gearbox. Currently running on Castrol Syntrax. No problems so far, although the H150F box is noticably slower-shifting than the R151F box, and has noticably lower ratios (with 33" tyres usually take off in second on the flat). T/D clutch slips a bit as the N/A diesel pulses at low revs on steep hills. Should possibly have gone for a heavy duty clutch.

It is in fact all too easy, I am surprised it worked out so well. It was obviously designed to drop straight in the first place (?).

Hints:

- you don't need to remove the exhaust - just the clamp on the bellhousing.
- I split/fitted the gearbox and transfer case independently because they are heavy, even on a jack (with transmission adaptor).
- maneuvering the gearbox in is tricky, work it out first with an unattached bellhousing, but remember it's harder once the input shaft's in there. Remember to put the box in gear first.

Good luck. Again - it was easy, don't believe all the rumour about driveshafts and welding crossmembers, making up new gearsticks etc, just choose your parts carefully and it will all bolt up perfectly. Casper

Many thnx to Andrew (Dozer) And Casper(Cowpat), for your input into my little drama!!! PRoblem now solved. TRUSTY (tongue in cheek) old 1hz up front, then all turbo diesel from there back, Now if i have trouble in the bush it'll be easy for replacement parts (ie. Clutch), plus everything is heavier so if have to do a motor transplant @ later date i've got the goods. (V8 chev diesel / or 1hdt). Many thanks and happy motoring. Keep it real!!! regards Kirsten

Just a quick plug for Toyhatsu Wrecking in Melbourne. Absolutely fantastic to deal with, and parts were some of the cheapest i priced. Very knowledgable,and i would recommend them with no hesitation! regards Kirsten (NSW)